JP3855729B2 - Objective lens drive device and disk drive device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an objective lens driving device and a disk drive device. More specifically, the present invention relates to a technical field of an objective lens driving device in which a movable portion having an objective lens is rotatably supported by a support shaft portion and a disk drive device including the objective lens driving device.
[0002]
[Prior art]
There is a disk drive device that records and reproduces information signals on and from a disk-shaped recording medium such as an optical disk. In such a disk drive device, the support shaft portion is rotatable about its axis and slid in the axial direction. Some of them are provided with an objective lens driving device that operates a movable part that is movably supported to perform focusing adjustment and tracking adjustment of a laser beam irradiated on a disk-shaped recording medium.
[0003]
FIG. 19 and FIG. 20 show such a conventional objective lens driving device.
[0004]
The objective lens driving device a includes a fixed part b formed of a magnetic metal material and a movable part c supported by the fixed part b.
[0005]
The fixed part b has a base part d, yoke parts e raised from both side edges of the base part d, and a support shaft part f protruding upward from a substantially central part of the base part d. . Magnets g and g are attached to the inner surfaces of the yoke portions e and e, respectively.
[0006]
The movable part c is formed by attaching necessary members to the bobbin h.
[0007]
The bobbin h has a main body part i and a lens holder part j protruding forward from the main body part i. At a substantially central portion of the main body portion i, a supported cylinder portion k is provided which has a cylindrical shape protruding downward. An objective lens 1 is held in the lens holder j.
[0008]
A coil body m is attached to the bobbin h. The coil body m has two tracking coils o, o,... Attached to both sides of the focusing coil n wound in a substantially rectangular tube shape so that the axial direction is vertical. Made up.
[0009]
A magnetic member p made of a magnetic metal material is attached to the supported cylindrical portion k of the bobbin h. The magnetic member p plays a role of holding the movable part c at a neutral position in the focusing direction and the tracking direction.
[0010]
The movable portion c is supported by the support shaft portion f so as to be slidable in the axial direction and rotatable about the axis by inserting the support shaft portion f of the fixed portion b into the supported cylindrical portion k. Yes. The axial direction of the support shaft portion f is a focusing direction in which focusing adjustment is performed on the disc-shaped recording medium, and the substantially radial direction of the disc-shaped recording medium is tracking direction in which tracking adjustment is performed on the disc-shaped recording medium. It is.
[0011]
In a state where the movable part c is supported by the support shaft part f, one end r of the flexible printed wiring board q is attached to the rear surface part of the bobbin h, and the intermediate part s of the flexible printed wiring board q is the base of the fixed part b. It is attached to the lower surface of the part d (see FIG. 20). The other end (not shown) of the flexible printed wiring board q is connected to a current supply circuit (not shown).
[0012]
One end r of the flexible printed wiring board q attached to the bobbin h is electrically connected to the focusing coil n and the tracking coils o, o,... And the focusing coil from the current supply circuit via the flexible printed wiring board q. A driving current is supplied to each of n and tracking coils o, o,.
[0013]
The shaft sliding type objective lens driving device a in which the movable portion c is supported by the support shaft portion f is compared with an objective lens driving device in which the movable portion is supported by a suspension with respect to the fixed portion. In addition, since the weight balance of the movable part c is good, the vibration resistance in the direction orthogonal to the focusing direction is excellent, and the displacement of the movable part c due to its own weight is small.
[0014]
[Problems to be solved by the invention]
However, in the above-described conventional objective lens driving device a, the flexible printed wiring board q attached to the movable part c for supplying a driving current to the focusing coil n and the tracking coils o, o,. Therefore, when the movable part c is operated with respect to the fixed part b, a large load is easily applied to the movable part c due to the rigidity of the flexible printed wiring board q, and the resonance frequency becomes high and the sensitivity in the low range is low. Inconveniences such as becoming may occur, which may hinder the operation of the movable part c.
[0015]
Further, when a force is applied in a direction in which the movable portion c is pressed against the support shaft portion f due to the rigidity of the flexible printed wiring board q, the neutral position of the movable portion c becomes unstable, or the movable portion c becomes the support shaft. There is also a problem that a pressing loss is caused in a state of being in line contact with the portion f, resulting in a large sliding loss and a decrease in sensitivity.
[0016]
Accordingly, an object of the objective lens driving device and the disk drive device of the present invention is to overcome the above-described problems and to stabilize the operation of the movable portion of the objective lens driving device.
[0017]
[Means for Solving the Problems]
In order to solve the above-described problems, the objective lens driving device according to the present invention includes a support shaft portion protruding in the optical axis direction of the objective lens, a focusing coil to which a driving current is supplied at the time of focusing adjustment, and a driving current at the time of tracking adjustment. And a fixed portion having a tracking coil supplied thereto, and are supported so as to be rotatable about the axis of the support shaft portion and slidable in the axial direction of the support shaft portion, and mounted on the disk table during focusing adjustment. A movable portion that is operated in a focusing direction, which is a direction in which the recording surface of the disk-shaped recording medium is separated from and touched, and is operated in a tracking direction, which is a substantially radial direction of the disk-shaped recording medium mounted on the disk table during tracking adjustment, The movable part is placed opposite to the focusing coil and tracking coil, and the pole pair Mounting but the second magnet And a magnetic member that is attached to the fixed portion and attracts the magnet to hold the movable portion at a neutral position in the focusing direction and the tracking direction, respectively, and has two poles on the surface side facing the focusing coil and the tracking coil of the magnet. The magnetic member is inclined with respect to the boundary line Is.
[0018]
Further, in order to solve the above-described problems, the disk drive device of the present invention is provided with a focusing shaft in which a driving current is supplied to the objective lens driving device and the support shaft portion provided to project in the optical axis direction of the objective lens during focusing adjustment. A fixed portion having a coil and a tracking coil to which a drive current is supplied during tracking adjustment, and is supported so as to be rotatable about the axis of the support shaft and slidable in the axial direction of the support shaft, and focusing adjustment Sometimes it is operated in the focusing direction, which is the direction of moving away from and contacting the recording surface of the disk-shaped recording medium mounted on the disk table, and is operated in the tracking direction, which is the substantially radial direction of the disk-shaped recording medium mounted on the disk table, during tracking adjustment. A movable part, and a focusing coil and a tracking coil in the movable part Install the pole pairs is 2 magnet while being oppositely disposed And a magnetic member that is attached to the fixed portion and attracts the magnet to hold the movable portion at a neutral position in the focusing direction and the tracking direction, respectively, and has two poles on the surface side facing the focusing coil and the tracking coil of the magnet. The magnetic member is inclined with respect to the boundary line Is.
[0019]
Therefore, in the objective lens driving device and the disk drive device of the present invention, it is not necessary to supply a driving current to the focusing coil and the tracking coil using the flexible printed wiring board.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an objective lens driving device and a disk drive device according to the present invention will be described below with reference to the accompanying drawings.
[0021]
First, a first embodiment will be described (see FIGS. 1 to 12).
[0022]
The disk drive device 1 is configured by arranging required members and mechanisms in an outer casing 2 having a thin box shape, and an insertion / removal port 2 a having a horizontally long rectangular shape is formed on the front surface of the outer casing 2. (See FIG. 1). The disc-shaped recording medium 100 is inserted into or removed from the outer casing 2 through the insertion / removal port 2a.
[0023]
A chassis 3 is disposed in the outer casing 2 (see FIG. 1). A spindle motor (not shown) is disposed on the lower surface side of the substantially central portion of the chassis 3, and the disk table 4 is fixed to the motor shaft of the spindle motor.
[0024]
An arrangement hole 3a is formed in the chassis 3, and the disk table 4 protrudes from the arrangement hole 3a to the upper side of the chassis 3 (see FIG. 1).
[0025]
A lead screw 5 and guide shafts 6 and 6 are arranged in parallel on the lower surface side of the chassis 3 (see FIG. 1). The optical pickup 7 is arranged in the arrangement hole 3a of the chassis 3 so as to be movable in the radial direction of the disk-shaped recording medium 100 mounted on the disk table 4 (see FIG. 1).
[0026]
The optical pickup 7 is formed by arranging required members on a moving base 8. In the optical pickup 7, one end portion of the moving base 8 is screwed to the lead screw 5, and both end portions of the moving base 8 are slidably supported by the guide shafts 6 and 6, respectively (see FIG. 1). Is guided by the guide shafts 6 and 6 and moved in the radial direction of the disc-shaped recording medium 100.
[0027]
The objective lens driving device 9 includes a fixed portion 10 and a movable portion 11 supported by the fixed portion 10 (see FIGS. 2 to 5).
[0028]
The fixed portion 10 is a base portion 12 attached to the upper surface of the moving base 8, yoke portions 13 and 13 formed by bending upward from both side edges of the base portion 12, and upward from a substantially central portion of the base portion 12. The base portion 12, the yoke portions 13 and 13, and the support shaft portion 14 are all made of a magnetic metal material.
[0029]
Coil bodies 15 and 15 are respectively attached to the inner surfaces of the yoke portions 13 and 13 (see FIGS. 2, 3 and 5).
[0030]
The coil body 15 is a coil called an FP coil, and focusing coils 17, 17,... Each having a small substantially rectangular tube shape and a tracking coil 18 having a large substantially rectangular tube shape are integrally formed on the substrate 16. (See FIGS. 6 to 8). Four focusing coils 17, 17,... Are provided at equal intervals in the circumferential direction, and the tracking coil 18 is provided so that substantially the whole overlaps with the focusing coils 17, 17,. ing.
[0031]
Four terminal portions 15a, 15a,... Are formed at the rear end portion of the coil body 15 so as to be separated from each other in the vertical direction, and both ends of the focusing coil 17 are connected to the two terminal portions 15a, 15a. The two end portions of the tracking coil 18 are connected to the other two terminal portions 15a and 15a.
[0032]
In the coil body 15, terminal portions 15a, 15a,... Are electrically connected to a current supply circuit (not shown), and a drive current is supplied from the current supply circuit to the focusing coils 17, 17,. .
[0033]
The movable part 11 is formed by attaching necessary members to a bobbin 19.
[0034]
The bobbin 19 has a main body part 20 and a lens holder part 21 protruding forward from the main body part 20 (see FIGS. 2 and 3).
[0035]
A supported hole 20a is formed at the center of the main body 20 (see FIG. 5). Magnets 22 and 22 and back yokes 23 and 23 are respectively attached to both side portions of the main body 20 (see FIGS. 2, 3 and 5).
[0036]
The magnets 22 and 22 have a rectangular shape that is long in the front and rear, and the number of pole pairs is 2, and the left and right both sides are magnetized differently in the front half and the rear half (see FIG. 3). The back yokes 23 and 23 are attached to the bobbin 19 in contact with the inner surfaces of the magnets 22 and 22, respectively.
[0037]
An objective lens 24 is attached to the lens holder portion 21 (see FIGS. 2 to 4).
[0038]
Magnetic members 25 and 25 are attached to the outer surfaces of the yoke parts 13 and 13 of the fixed part 10, respectively. The magnetic member 25 has, for example, a thin rectangular shape formed of an iron material, and the yoke is tilted with respect to a boundary line 22a of two poles in the front-rear direction of the magnet 22 provided in the movable portion 11. It is attached to the parts 13 and 13 (see FIG. 4).
[0039]
The movable portion 11 is supported by the support shaft portion 14 such that the support shaft portion 14 is slidable in the axial direction and rotatable about the axis by inserting the support shaft portion 14 into the supported hole 20a (FIG. 2, FIG. 3 and FIG. 5). The axial direction of the support shaft portion 14 is a focusing direction (FF direction shown in FIG. 2) in which focusing adjustment is performed with respect to the disc-shaped recording medium 100, and the substantially radial direction of the disc-shaped recording medium 100 is disc-shaped recording. This is the tracking direction (TT direction shown in FIG. 2) in which tracking adjustment is performed on the medium 100.
[0040]
In a state where the movable portion 11 is supported by the support shaft portion 14, the magnets 22 and 22 are positioned to face the focusing coils 17, 17,... Of the coil bodies 15, 15 and the tracking coils 18, 18, respectively. The The movable part 11 is operated in the focusing direction by the relationship between the magnetic forces of the magnets 22 and 22 and the drive currents flowing before and after the focusing coils 17, 17,... (See FIG. 7). The coil 18 is operated in the tracking direction according to the relationship with the drive current flowing above and below the coils 18 (see FIG. 8).
[0041]
A flat cover 26 that covers the movable portion 11 is attached to the upper surfaces of the yoke portions 13 and 13 of the fixed portion 10 (see FIGS. 2, 4, and 5).
[0042]
The operation of the disk drive device 1 will be described below.
[0043]
When the disk-shaped recording medium 100 is mounted on the disk table 4 and a recording switch or a reproduction switch (not shown) is operated, the disk-shaped recording medium 100 is rotated with the rotation of the disk table 4 driven by the spindle motor. When the disk-shaped recording medium 100 is rotated, laser light is emitted from a light emitting element (not shown) provided on the moving base 8 and is irradiated onto the recording surface of the disk-shaped recording medium 100 via the objective lens 24.
[0044]
Laser light applied to the recording surface of the disk-shaped recording medium 100 is reflected by the recording surface, is incident on a light receiving element (not shown) provided on the moving base 8, and is photoelectrically converted to record or reproduce an information signal. .
[0045]
When the information signal is recorded or reproduced, focusing adjustment and tracking adjustment are performed by the objective lens driving device 9. At the time of focusing adjustment, a drive current is supplied from the current supply circuit to the focusing coils 17, 17,... Of the coil bodies 15, 15, and the spot of the laser light irradiated through the objective lens 24 is changed to the disc-shaped recording medium 100. The movable portion 11 is moved in the axial direction of the support shaft portion 14 so as to concentrate on the recording surface. At the time of tracking adjustment, a drive current is supplied from the current supply circuit to the tracking coils 18 and 18 of the coil bodies 15 and 15, and a laser beam spot irradiated through the objective lens 24 is collected on the recording surface of the disc-shaped recording medium 100. The movable part 11 is moved in the direction around the axis of the support shaft part 14 so as to shine.
[0046]
In the objective lens driving device 9, the magnetic members 25 and 25 are attached to the yoke portions 13 and 13 of the fixed portion 10, respectively, so that the central portions of the magnets 22 and 22 are attracted to the magnetic members 25 and 25. Therefore, when no driving current is supplied to the focusing coils 17, 17,..., The movable portion 11 can be reliably held at the neutral position in the focusing direction, and the driving current is applied to the tracking coils 18, 18. When not supplied, the movable part 11 can be reliably held at the neutral position in the tracking direction.
[0047]
In this neutral position, the magnet 22 provided on the movable portion 11 faces the substantially central portion of the entire four focusing coils 17, 17,... Of the coil body 15 and the substantially central portion of the tracking coil 18. (See FIGS. 7 and 8).
[0048]
As described above, the magnetic members 25 and 25 are attached to the yoke portions 13 and 13 while being inclined with respect to the boundary lines 22a and 22a of the magnets 22 and 22 provided in the movable portion 11, respectively. The magnets 22 and 22 are attracted so that the boundary lines 22a and 22a are along the magnetic members 25 and 25, and the movable portion 11 is inclined with respect to the support shaft portion 14 by the clearance between the support shaft portion 14 and the supported hole 20a. (See FIG. 9).
[0049]
Therefore, the movable part 11 is operated in the focusing direction and the tracking direction in a state where the movable part 11 is always inclined to one side with respect to the support shaft part 14, the vibration resistance is improved, and the change in the inclination direction of the movable part 11 with respect to the support shaft part 14 is changed. Operates stably without coming.
[0050]
As described above, in the objective lens driving device 9, the fixed portion 10 is provided with the coil bodies 15, 15 having the focusing coils 17, 17,... And the tracking coils 18, 18. There is no need to attach a flexible printed wiring board for supplying current to the movable part 11, no load is applied to the movable part 11 during operation, and the operation can be stabilized by improving the sensitivity of the movable part 11. it can.
[0051]
Further, since it is not necessary to secure a space for arranging the flexible printed wiring board, the objective lens driving device 9 can be downsized accordingly.
[0052]
Furthermore, the number of pole pairs of the magnets 22 and 22 provided in the movable portion 11 is 2, and the magnetic flux in the magnets 22 and 22 draws a small loop between the north and south poles adjacent in the front-rear direction. (See FIG. 3).
[0053]
Therefore, for example, when a magnet having a pole pair number of 1 is used, it does not become a magnetic flux that draws a large loop from the magnet to the yoke portion 13, the base portion 12, the support shaft portion 14, and the magnet. Therefore, when the weight balance of the movable part 11 with respect to the support shaft part 14 is lost, it is difficult to deteriorate the balance, and a good operating state of the movable part 11 can be maintained. .
[0054]
Further, since the magnetic flux is generated so as to draw a loop between the N pole and the S pole adjacent in the front-rear direction, the movable portion 11 can operate even if a part of the yoke is omitted. When the portion is omitted, the objective lens driving device 9 can be downsized.
[0055]
In the above, as a method of operating the movable portion 11 in an inclined state with respect to the support shaft portion 14 by the clearance between the support shaft portion 14 and the supported hole 20a, the magnetic members 25 and 25 are respectively connected to the magnet 22. In this example, the movable portion 11 is attached to the support shaft portion 14 with respect to the support shaft portion 14 while being supported on the outer surface of the yoke portions 13 and 13 while being inclined with respect to the boundary lines 22a and 22a. For example, the magnetic members 25 and 25 may be arranged at positions corresponding to the front or rear of the boundary lines 22a and 22a, and the magnetic members 25 and 25 may be operated in a state of being inclined by the clearance with the hole 20a. Such as changing the material and size of the left and right magnetic members 25, 25, and the distance to the magnets 22, 22, etc. The law can be used.
[0056]
Next, a magnet 22A, which is a modification of the magnet 22, will be described (see FIGS. 10 to 12).
[0057]
The magnets 22A and 22A are bent so that the central portions in the front-rear direction protrude outward. In the objective lens driving device 9A using the magnets 22A and 22A, when the movable portion 11A is rotated around the axis with respect to the support shaft portion 14 and is operated in the tracking direction, the coil body 15, Since the surface of the 15 magnets 22A and 22A facing the magnets 22A and 22A is substantially parallel to the outer surface of the magnets 22A and 22A (see FIGS. 11 and 12), the distance between the magnets 22A and 22A and the coil bodies 15 and 15 is increased accordingly. The size can be reduced and the size can be reduced.
[0058]
In addition, in order to project the central part in the front-rear direction outward as described above, the front half part and the rear half part are respectively formed by magnets having one pole pair, and both are inclined with respect to each other. It can also be configured by attaching to the bobbin 19.
[0059]
Next, a second embodiment will be described (see FIGS. 13 to 18). The objective lens driving device 9B shown below is different from the above-described objective lens driving device 9 only in that the magnet magnetization direction is different and the configuration of the coil body is different. Only parts that are different from the apparatus 9 will be described in detail, and the other parts will be denoted by the same reference numerals as the same parts in the objective lens driving device 9 and description thereof will be omitted.
[0060]
In the objective lens driving device 9B, coil bodies 27 and 27 are attached to the inner surfaces of the yoke portions 13 and 13, respectively (see FIGS. 13 and 15).
[0061]
The coil body 27 is a coil called an FP coil, and a focusing coil 29 having a large substantially rectangular tube shape and tracking coils 30, 30,. (See FIGS. 16 to 18). Four tracking coils 30, 30,... Are provided at equal intervals in the circumferential direction, and the focusing coil 29 is provided so that substantially the whole overlaps with the tracking coils 30, 30,. ing.
[0062]
Four terminal portions 27a, 27a,... Are formed at the rear end portion of the coil body 27 so as to be separated from each other in the vertical direction, and both end portions of the focusing coil 29 are connected to the two terminal portions 27a, 27a. In addition, both end portions of the tracking coil 30 are connected to the other two terminal portions 27a and 27a.
[0063]
In the coil body 27, terminal portions 27a, 27a,... Are electrically connected to a current supply circuit (not shown), and a drive current is supplied from the current supply circuit to the focusing coil 29 and the tracking coils 30, 30,. .
[0064]
The movable portion 11B is formed by attaching necessary members to the bobbin 19.
[0065]
Magnets 31 are respectively attached to both side portions of the main body 20 of the bobbin 19 (see FIGS. 13 and 15). The magnets 31 and 31 have a rectangular shape that is long in the vertical direction, and the number of pole pairs is 2, and the left and right sides are magnetized differently in the upper half and the lower half (see FIG. 15). .
[0066]
Magnetic members 25 and 25 are attached to the outer surfaces of the yoke portions 13 and 13 of the fixed portion 10B, respectively. The magnetic member 25 has, for example, a thin rectangular shape made of an iron material, and is inclined with respect to the boundary line 31a between the two poles in the vertical direction of the magnet 31 provided on the movable portion 11B. It is attached to the parts 13 and 13 (see FIG. 14).
[0067]
The movable portion 11B is supported by the support shaft portion 14 such that the support shaft portion 14 is slidable in the axial direction and rotatable about the axis by inserting the support shaft portion 14 into the supported hole 20a (FIG. 13 and FIG. 13). 15).
[0068]
In a state where the movable portion 11B is supported by the support shaft portion 14, the magnets 31, 31 are positioned to face the focusing coils 29, 29 of the coil bodies 27, 27 and the tracking coils 30, 30,. The The movable portion 11B is operated in the focusing direction by the relationship between the magnetic force of the magnets 31 and 31 and the drive current flowing before and after the focusing coil 29 (see FIG. 18), and the magnetic force of the magnets 31 and 31 and the tracking coils 30, 30,. .. Are operated in the tracking direction according to the relationship with the drive currents flowing above and below (see FIG. 17).
[0069]
In the objective lens driving device 9B, since the magnetic members 25 and 25 are attached to the yoke portions 13 and 13 of the fixed portion 10B, the central portions of the magnets 31 and 31 are attracted to the magnetic members 25 and 25, respectively. Therefore, when the drive current is not supplied to the focusing coils 29, 29, the movable portion 11 can be reliably held at the neutral position in the focusing direction, and the drive current is applied to the tracking coils 30, 30,. When not supplied, the movable part 11 can be reliably held at the neutral position in the tracking direction.
[0070]
In this neutral position, the magnet 31 provided on the movable portion 11B faces the substantially central portion of the focusing coil 29 of the coil body 27 and the substantially central portion of the entire four tracking coils 30, 30,. (See FIGS. 17 and 18).
[0071]
As described above, the magnetic members 25 and 25 are attached to the yoke portions 13 and 13 while being inclined with respect to the boundary lines 31a and 31a of the magnets 31 and 31 provided in the movable portion 11B, respectively. The magnets 31 and 31 are attracted so that the boundary lines 31a and 31a are along the magnetic members 25 and 25, and the movable portion 11B is inclined with respect to the support shaft portion 14 by the clearance between the support shaft portion 14 and the supported hole 20a. The
[0072]
Therefore, the movable portion 11B is operated in the focusing direction and the tracking direction in a state where the movable portion 11B is always inclined to one side, the vibration resistance is improved, and the change in the inclination direction of the movable portion 11B relative to the support shaft portion 14 is improved. Operates stably without coming.
[0073]
In the objective lens driving device 9B described above, since the coil bodies 27, 27 having the focusing coils 29, 29 and the tracking coils 30, 30,... Are provided in the fixed portion 10B, a driving current is supplied. Therefore, there is no need to attach the flexible printed wiring board to the movable part 11B, and no load is applied to the movable part 11B during operation, and the operation can be stabilized by improving the sensitivity of the movable part 11B.
[0074]
Further, since it is not necessary to secure a space for arranging the flexible printed wiring board, the objective lens driving device 9B can be reduced in size accordingly.
[0075]
Furthermore, since the number of pole pairs of the magnets 31 and 31 provided in the movable portion 11B is 2, when the weight balance with respect to the support shaft portion 14 of the movable portion 11B is lost for the same reason as the objective lens driving device 9. Therefore, it is difficult to deteriorate the balance, and it is possible to maintain a good operating state of the movable part 11B. Further, even if a part of the yoke is omitted, the movable part 11B can operate, so a part of the yoke is omitted. In this case, it is possible to reduce the size of the objective lens driving device 9B.
[0076]
In addition, in the objective lens driving device 9B, since the magnets 27 and 27 have a vertically long shape and the front and rear widths are small, when the movable portion 11B is rotated in the direction around the axis of the support shaft portion 14, the coil The bodies 27 and 27 and the magnets 31 and 31 hardly interfere with each other. Accordingly, the distance between the coil bodies 27 and 27 and the magnets 31 and 31 can be reduced correspondingly, and the objective lens driving device 9B can be downsized.
[0077]
The specific shapes and structures of the respective parts shown in the respective embodiments described above are merely examples of the implementation of the present invention, and the technical scope of the present invention is thereby limited. It should not be interpreted in a limited way.
[0078]
【The invention's effect】
As is apparent from the above description, the objective lens driving device of the present invention has a moving base that moves in the radial direction of a disk-shaped recording medium mounted on the disk table, and includes a light emitting element provided on the moving base. Provided in an optical pickup that irradiates the irradiated laser beam onto the recording surface of the disc-shaped recording medium via the objective lens, and performs focusing adjustment and tracking adjustment so that the laser beam is focused on the recording surface of the disc-shaped recording medium. An objective lens driving device, comprising: a support shaft portion protruding in the optical axis direction of the objective lens; a focusing coil to which a drive current is supplied during focusing adjustment; and a tracking coil to which a drive current is supplied during tracking adjustment A fixed portion having the support shaft portion, and a support shaft portion that is rotatable in a direction around the axis of the support shaft portion. Disc-shaped recording supported in the axial direction and slidably mounted in the focusing table, which is operated in the focusing direction, which is the direction of moving away from and contacting the recording surface of the disc-shaped recording medium mounted on the disc table during focusing adjustment. A movable portion that is operated in a tracking direction that is a substantially radial direction of the medium, and is disposed opposite to the focusing coil and the tracking coil, and a magnet having two pole pairs is attached to the movable portion. And a magnetic member that is attached to the fixed portion and attracts the magnet to hold the movable portion at a neutral position in the focusing direction and the tracking direction, respectively, and has two poles on the surface side facing the focusing coil and the tracking coil of the magnet. The magnetic member is inclined with respect to the boundary line It is characterized by that.
[0079]
Therefore, it is not necessary to attach the flexible printed wiring board to the movable part, and no load is applied to the movable part during operation, and the operation can be stabilized by improving the sensitivity of the movable part.
[0080]
Further, since it is not necessary to secure a space for arranging the flexible printed wiring board, the objective lens driving device can be reduced in size accordingly.
[0081]
In addition, the number of pole pairs of the magnet provided in the movable part is 2, and the magnetic flux in the magnet is generated in a small loop between the adjacent N pole and S pole, and the magnet's attractive force is required Since it does not become larger than the above, it is difficult to deteriorate the balance when the weight balance of the movable portion with respect to the support shaft portion is broken, and a good operating state of the movable portion can be maintained.
[0082]
In addition, since the magnetic flux is generated so as to draw a loop between the adjacent N pole and S pole, a part of the yoke can be omitted, and the objective lens driving device can be reduced in size by omitting a part of the yoke. Can be achieved.
[0083]
And A magnetic member that is attached to the fixed portion and attracts the magnet to hold the movable portion at the neutral position in the focusing direction and the tracking direction is provided, so that the movable portion is securely held at the neutral position in the focusing direction and the tracking direction. be able to.
[0084]
And furthermore, Since the magnetic member is inclined with respect to the boundary line between the two poles on the surface facing the focusing coil and the tracking coil of the magnet, the focusing direction and the tracking direction with the movable portion inclined with respect to the support shaft portion Thus, the vibration resistance is improved, and a stable operation can be ensured without causing a change in the inclination direction of the movable portion with respect to the support shaft portion.
[0085]
The disk drive apparatus of the present invention has a moving base that moves in the radial direction of a disk-shaped recording medium mounted on a disk table, and receives a laser beam emitted from a light emitting element provided on the moving base via an objective lens. An optical pickup for irradiating the recording surface of the recording medium, and focusing adjustment and tracking adjustment are performed by the objective lens driving device provided in the optical pickup so that the laser beam is focused on the recording surface of the disk-shaped recording medium In the disk drive device, the objective lens driving device is provided with a supporting shaft portion that protrudes in the optical axis direction of the objective lens, a focusing coil that is supplied with a driving current at the time of focusing adjustment, and a driving current that is supplied at the time of tracking adjustment. A fixed portion having a tracking coil, and Focusing is a direction that is supported so as to be rotatable about the axis of the holding shaft and to be slidable in the axial direction of the support shaft, and to come in contact with the recording surface of the disc-shaped recording medium mounted on the disc table during focusing adjustment. And a movable portion operated in the tracking direction, which is a substantially radial direction of the disk-shaped recording medium mounted on the disk table during tracking adjustment, and disposed on the movable portion so as to face the focusing coil and the tracking coil. And a magnet with 2 pole pairs And a magnetic member that is attached to the fixed portion and attracts the magnet to hold the movable portion at a neutral position in the focusing direction and the tracking direction, respectively, and has two poles on the surface side facing the focusing coil and the tracking coil of the magnet. The magnetic member is inclined with respect to the boundary line It is characterized by that.
[0086]
Therefore, it is not necessary to attach the flexible printed wiring board to the movable part, and no load is applied to the movable part during operation, and the operation can be stabilized by improving the sensitivity of the movable part.
[0087]
In addition, since it is not necessary to secure a space for arranging the flexible printed wiring board, the disk drive device can be reduced in size as the objective lens driving device is reduced.
[0088]
In addition, the number of pole pairs of the magnet provided in the movable part is 2, and the magnetic flux in the magnet is generated in a small loop between the adjacent N pole and S pole, and the magnet's attractive force is required Since it does not become larger than the above, it is difficult to deteriorate the balance when the weight balance of the movable portion with respect to the support shaft portion is broken, and a good operating state of the movable portion can be maintained.
[0089]
In addition, since the magnetic flux is generated so as to draw a loop between the adjacent N pole and S pole, a part of the yoke can be omitted, and the objective lens driving device can be reduced in size by omitting a part of the yoke. Accordingly, it is possible to reduce the size of the disk drive device.
[0090]
And A magnetic member that is attached to the fixed portion and attracts the magnet to hold the movable portion at the neutral position in the focusing direction and the tracking direction is provided, so that the movable portion is securely held at the neutral position in the focusing direction and the tracking direction. be able to.
[0091]
And furthermore, Since the magnetic member is inclined with respect to the boundary line between the two poles on the surface facing the focusing coil and the tracking coil of the magnet, the focusing direction and the tracking direction with the movable portion inclined with respect to the support shaft portion Thus, the vibration resistance is improved, and a stable operation can be ensured without causing a change in the inclination direction of the movable portion with respect to the support shaft portion.
[Brief description of the drawings]
FIG. 1 shows a first embodiment of the present invention together with FIGS. 2 to 12, and is a schematic perspective view of a disk drive device.
FIG. 2 is an enlarged perspective view of an objective lens driving device showing a cover separately.
FIG. 3 is an enlarged plan view of the objective lens driving device shown with a cover removed.
FIG. 4 is an enlarged side view of the objective lens driving device.
5 is a cross-sectional view taken along line VV in FIG. 3 with a cover attached.
FIG. 6 is an enlarged side view of a coil body.
FIG. 7 is an enlarged side view of a coil body showing a relationship between a focusing coil and a magnet without a tracking coil.
FIG. 8 is an enlarged side view of a coil body showing a relationship between a tracking coil and a magnet without a focusing coil.
FIG. 9 is a conceptual diagram showing a state in which the movable part is inclined with respect to the support shaft part.
FIG. 10 shows an objective lens driving device using another magnet together with FIGS. 11 and 12, and this figure is an enlarged plan view showing a state where a cover is removed.
FIG. 11 is an enlarged plan view showing a state in which the movable portion is rotated to one side with respect to the support shaft portion.
FIG. 12 is an enlarged plan view showing a state in which the movable portion is rotated to the other side with respect to the support shaft portion.
FIG. 13 shows a second embodiment of the present invention together with FIGS. 14 to 18, and is an enlarged plan view of an objective lens driving device shown with a cover removed.
FIG. 14 is an enlarged side view of the objective lens driving device.
15 is a cross-sectional view taken along line XV-XV in FIG. 13 with the cover attached.
FIG. 16 is an enlarged side view of a coil body.
FIG. 17 is an enlarged side view of a coil body showing a relationship between a tracking coil and a magnet without a focusing coil.
18 is an enlarged side view of a coil body showing a relationship between a focusing coil and a magnet, omitting a tracking coil. FIG.
FIG. 19 shows a conventional objective lens driving device together with FIG. 20, and is a schematic enlarged plan view.
FIG. 20 is a schematic enlarged cross-sectional view.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Disk drive apparatus, 4 ... Disk table, 7 ... Optical pick-up, 8 ... Moving base, 9 ... Objective lens drive device, 10 ... Fixed part, 11 ... Movable part, 14 ... Supporting shaft part, 17 ... Focusing coil, 18 ... Tracking coil, 22 ... Magnet, 22a ... Boundary line, 24 ... Objective lens, 25 ... Magnetic member, 100 ... Disc-shaped recording medium, 9A ... Objective lens driving device, 11A ... Movable part, 22A ... Magnet, 9B ... Objective lens Drive device, 10B ... fixed part, 11B ... movable part, 29 ... focusing coil, 30 ... tracking coil, 31 ... magnet, 31a ... border line

Claims (2)

A moving base that moves in the radial direction of a disc-shaped recording medium mounted on the disc table and laser light emitted from a light emitting element provided on the moving base is applied to the recording surface of the disc-shaped recording medium via an objective lens. An objective lens driving device that is provided in an optical pickup that irradiates and performs focusing adjustment and tracking adjustment so that laser light is condensed on a recording surface of a disk-shaped recording medium,
A fixed portion having a support shaft portion projecting in the optical axis direction of the objective lens, a focusing coil to which a driving current is supplied during focusing adjustment, and a tracking coil to which a driving current is supplied during tracking adjustment;
This is a direction that is supported so as to be rotatable about the axis of the support shaft and slidable in the axial direction of the support shaft, and to be in contact with and away from the recording surface of the disk-shaped recording medium mounted on the disk table during focusing adjustment. A movable portion operated in the focusing direction and operated in the tracking direction, which is a substantially radial direction of the disk-shaped recording medium mounted on the disk table at the time of tracking adjustment,
A magnet having a number of pole pairs of 2 is attached to the movable part so as to face the focusing coil and the tracking coil ,
Provided with a magnetic member that is attached to the fixed portion and holds the movable portion at a neutral position in the focusing direction and the tracking direction by attracting the magnet,
An objective lens driving device characterized in that the magnetic member is inclined with respect to a boundary line between two poles on the surface side facing the focusing coil and tracking coil of the magnet . A moving base that moves in the radial direction of a disc-shaped recording medium mounted on the disc table and a laser beam emitted from a light emitting element provided on the moving base is applied to the recording surface of the disc-shaped recording medium via an objective lens. A disk drive device that includes an optical pickup that irradiates and performs focusing adjustment and tracking adjustment so that laser light is condensed on a recording surface of a disk-shaped recording medium by an objective lens driving device provided in the optical pickup,
The objective lens driving device is:
A fixed portion having a support shaft portion projecting in the optical axis direction of the objective lens, a focusing coil to which a driving current is supplied at the time of focusing adjustment, and a tracking coil to which a driving current is supplied at the time of tracking adjustment;
This is a direction that is supported so as to be rotatable about the axis of the support shaft and slidable in the axial direction of the support shaft, and to be in contact with and away from the recording surface of the disk-shaped recording medium mounted on the disk table at the time of focusing adjustment. A movable part that is operated in the focusing direction and is operated in the tracking direction, which is a substantially radial direction of the disk-shaped recording medium mounted on the disk table during tracking adjustment,
A magnet having a number of pole pairs of 2 is attached to the movable part so as to face the focusing coil and the tracking coil,
A magnetic member is provided that is attached to the fixed portion and attracts the magnet to hold the movable portion at a neutral position in the focusing direction and the tracking direction,
The magnetic member is inclined with respect to a boundary line between two poles on the surface side facing the focusing coil and tracking coil of the magnet.
A disk drive device characterized by that.

Images